Step 1In a medium bowl, combine the raisins, currants, candied peel and candied cranberries. Pour the brandy over the fruit and let stand 1 hour. Drain, reserving the brandy. Pat the fruit dry with paper towels, return to a clean bowl and toss with 2 tablespoons of the flour.
Step 2In the bowl of a standing mixer or in a large bowl, sprinkle the yeast over one-fourth cup warm water (110 to 115 degrees) and stir until dissolved. Stir in 1 teaspoon of the sugar. Let stand until the yeast begins to bubble, about 5 minutes.
Step 3In a small saucepan over medium heat, heat the milk, salt and remaining sugar to warm (110 to 115 degrees). Add the milk mixture, vanilla extract and eggs to the yeast mixture and beat in a mixer or by hand with a fork or wooden spoon until combined. Beat in the reserved brandy. Add 2 cups of the flour and beat until smooth. Cut the butter into small pieces and beat in. Beat in enough of the remaining flour until the dough forms a ball.
Step 4Turn the dough out onto a lightly floured surface and knead until smooth and elastic, about 10 minutes. Flatten the dough out, then knead in the candied fruit, adding flour to the board as needed.
Step 5Shape the dough into a ball and put the dough into a buttered glass bowl. Turn the dough buttered side up and loosely cover. Let rise until doubled in size, about 2 hours.
Step 6Punch down the dough and divide into two equal parts. Place one half aside. Roll the other half into a 12-by-8-inch oval. Brush with melted butter.
Step 7Cut the marzipan into quarters and roll each quarter into a 12-inch rope. Put two of the ropes alongside each other along the length of the dough, leaving a 1 1/2 - to 2-inch border between the two ropes in the center of the rolled-out dough. Fold the long side of the dough over to the center of the oval. Fold over the other long side so that it overlaps the center by about 1 inch, pressing down gently but firmly. Lightly taper the ends of the loaf. Put the finished loaf on a parchment-lined baking sheet. Brush with melted butter. Repeat with the reserved dough.
Step 8Let the two loaves rise until each has doubled in size. Heat the oven to 375 degrees. Bake about 30 to 40 minutes until dark golden brown. Dust loaves with powdered sugar.